A. O. OUDRMANS, NOTKS O.V ACARI. 77 



nympha, nynipha, adults, deutonyrapha. female, tritonympha, 

 adults, intermediate forms between tritonympha and adults!!! 



Of other species, e. g. Gamasus coleoptratorum^ he adopts 

 other series and other stages. 



Also he adopts paedogenesis. 



Alas these hypotheses have made considerable confusion ! I 

 myself I have toppled down head foreuiost in this undisen- 

 tanglable chaos ! 



But since the past year I have endeavoured to delineate — 

 with scrupulous exactitude the different forms of Gemasids I 

 met with, with the result that I gradually saw light in the 

 darkness and detected that Michaki, is right in having shown 

 that there is but one series in the development of the 

 riamasids, viz. egg — larva — protonympha - deutonympha 

 — male and female. The larva is recognizable by its 

 having only three pairs of legs. — Th(^ protonympha only 

 by its having a very short peritrema. — The deutonympha 

 by its being provided with a long peritrema. — The adults 

 by showing their genitalia. — The different stages belonging 

 to one species are nearly always immediately recognizable by 

 their so called epistema or by other typical caracteristics. 

 Indeed the number of Gamasids does not stops in one hundred, 

 there are much more, but the differences of the species are 

 sometimes minute. 



I hasten to say that if I have well interpreted the last papers 

 of Berlese, I have observed that he himself gradually abandons 

 his ideas uttered in the above named papers of 1881 and 1882. 



In 1884 appeared the First Volume of that Standard Work 

 »British Oribatidae» of the pen of the indefatigable 

 Englisli author Michaei.. Though he treats in his volume several 

 cases of having bred Oribatidae, not one single passage quotes 

 his having made acquaintance with parthenogenesis in this 

 family. It is a pity that he has not tried it, 



